When editing vector tile symbols, correctly populate the @zoom_level

variable to match the current canvas zoom level Makes it easier to write and debug data defined expressions based on zoom level.
qgis · Sep 9, 2020 · 5df98cf · 5df98cf
1 parent 92c3a88
commit 5df98cf
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diff --git a/src/gui/vectortile/qgsvectortilebasiclabelingwidget.cpp b/src/gui/vectortile/qgsvectortilebasiclabelingwidget.cpp
@@ -396,6 +396,16 @@ void QgsVectorTileBasicLabelingWidget::editStyleAtIndex( const QModelIndex &prox
   context.setMapCanvas( mMapCanvas );
   context.setMessageBar( mMessageBar );
 
+  if ( mMapCanvas )
+  {
+    const int zoom = QgsVectorTileUtils::scaleToZoomLevel( mMapCanvas->scale(), 0, 99 );
+    QList<QgsExpressionContextScope> scopes = context.additionalExpressionContextScopes();
+    QgsExpressionContextScope tileScope;
+    tileScope.setVariable( "zoom_level", zoom, true );
+    scopes << tileScope;
+    context.setAdditionalExpressionContextScopes( scopes );
+  }
+
   QgsVectorLayer *vectorLayer = nullptr;  // TODO: have a temporary vector layer with sub-layer's fields?
 
   QgsPanelWidget *panel = QgsPanelWidget::findParentPanel( this );

diff --git a/src/gui/vectortile/qgsvectortilebasicrendererwidget.cpp b/src/gui/vectortile/qgsvectortilebasicrendererwidget.cpp
@@ -410,6 +410,16 @@ void QgsVectorTileBasicRendererWidget::editStyleAtIndex( const QModelIndex &prox
   context.setMapCanvas( mMapCanvas );
   context.setMessageBar( mMessageBar );
 
+  if ( mMapCanvas )
+  {
+    const int zoom = QgsVectorTileUtils::scaleToZoomLevel( mMapCanvas->scale(), 0, 99 );
+    QList<QgsExpressionContextScope> scopes = context.additionalExpressionContextScopes();
+    QgsExpressionContextScope tileScope;
+    tileScope.setVariable( "zoom_level", zoom, true );
+    scopes << tileScope;
+    context.setAdditionalExpressionContextScopes( scopes );
+  }
+
   QgsVectorLayer *vectorLayer = nullptr;  // TODO: have a temporary vector layer with sub-layer's fields?
 
   QgsPanelWidget *panel = QgsPanelWidget::findParentPanel( this );